From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752192AbcFWT7N (ORCPT ); Thu, 23 Jun 2016 15:59:13 -0400 Received: from mail-wm0-f54.google.com ([74.125.82.54]:36526 "EHLO mail-wm0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751286AbcFWT7J (ORCPT ); Thu, 23 Jun 2016 15:59:09 -0400 MIME-Version: 1.0 In-Reply-To: References: <1466556426-32664-1-git-send-email-keescook@chromium.org> <20160622124707.GC9922@io.lakedaemon.net> <20160623193358.GL9922@io.lakedaemon.net> From: Kees Cook Date: Thu, 23 Jun 2016 12:59:07 -0700 X-Google-Sender-Auth: q091MBOShRNTZ_bM9kzrthXdCME Message-ID: Subject: Re: [kernel-hardening] [PATCH v7 0/9] x86/mm: memory area address KASLR To: Sandy Harris Cc: "kernel-hardening@lists.openwall.com" , Thomas Garnier , Ingo Molnar , Andy Lutomirski , "x86@kernel.org" , Borislav Petkov , Baoquan He , Yinghai Lu , Juergen Gross , Matt Fleming , Toshi Kani , Andrew Morton , Dan Williams , "Kirill A. Shutemov" , Dave Hansen , Xiao Guangrong , Martin Schwidefsky , "Aneesh Kumar K.V" , Alexander Kuleshov , Alexander Popov , Dave Young , Joerg Roedel , Lv Zheng , Mark Salter , Dmitry Vyukov , Stephen Smalley , Boris Ostrovsky , Christian Borntraeger , Jan Beulich , LKML , Jonathan Corbet , "linux-doc@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 23, 2016 at 12:45 PM, Sandy Harris wrote: > Jason Cooper wrote: > >> Modern systems that receive a seed from the bootloader via the >> random-seed property (typically from the hw-rng) can mix both sources >> for increased resilience. >> >> Unfortunately, I'm not very familiar with the internals of x86 >> bootstrapping. Could GRUB be scripted to do a similar task? How would >> the address and size of the seed be passed to the kernel? command line? > > One suggestion is at: > http://www.av8n.com/computer/htm/secure-random.htm#sec-boot-image Interesting! This might pose a problem for signed images, though. (Actually, for signed arm kernels is the DT signed too? If so, it would be a similar problem.) -Kees -- Kees Cook Chrome OS & Brillo Security From mboxrd@z Thu Jan 1 00:00:00 1970 Reply-To: kernel-hardening@lists.openwall.com MIME-Version: 1.0 Sender: keescook@google.com In-Reply-To: References: <1466556426-32664-1-git-send-email-keescook@chromium.org> <20160622124707.GC9922@io.lakedaemon.net> <20160623193358.GL9922@io.lakedaemon.net> From: Kees Cook Date: Thu, 23 Jun 2016 12:59:07 -0700 Message-ID: Content-Type: text/plain; charset=UTF-8 Subject: Re: [kernel-hardening] [PATCH v7 0/9] x86/mm: memory area address KASLR To: Sandy Harris Cc: "kernel-hardening@lists.openwall.com" , Thomas Garnier , Ingo Molnar , Andy Lutomirski , "x86@kernel.org" , Borislav Petkov , Baoquan He , Yinghai Lu , Juergen Gross , Matt Fleming , Toshi Kani , Andrew Morton , Dan Williams , "Kirill A. Shutemov" , Dave Hansen , Xiao Guangrong , Martin Schwidefsky , "Aneesh Kumar K.V" , Alexander Kuleshov , Alexander Popov , Dave Young , Joerg Roedel , Lv Zheng , Mark Salter , Dmitry Vyukov , Stephen Smalley , Boris Ostrovsky , Christian Borntraeger , Jan Beulich , LKML , Jonathan Corbet , "linux-doc@vger.kernel.org" List-ID: On Thu, Jun 23, 2016 at 12:45 PM, Sandy Harris wrote: > Jason Cooper wrote: > >> Modern systems that receive a seed from the bootloader via the >> random-seed property (typically from the hw-rng) can mix both sources >> for increased resilience. >> >> Unfortunately, I'm not very familiar with the internals of x86 >> bootstrapping. Could GRUB be scripted to do a similar task? How would >> the address and size of the seed be passed to the kernel? command line? > > One suggestion is at: > http://www.av8n.com/computer/htm/secure-random.htm#sec-boot-image Interesting! This might pose a problem for signed images, though. (Actually, for signed arm kernels is the DT signed too? If so, it would be a similar problem.) -Kees -- Kees Cook Chrome OS & Brillo Security